Molding and casting process



Dec. 22, 1959 H. L. GOLDWAG MOLDING AND CASTING PROCESS Filed June '7.1956 INVENTOR.

HAZE) L. GOLDWAG BY EMMA ATTORNEY MOLDING AND CASTING PROCESS Harry L.Goldwag, New York, N.Y.

Application June 7, 1956, Serial No. 589,935

1 Claim. (Cl. 18-5505) My invention relates to a new process for makingcasts with the use of a phenolic foam as I will describe hereinbelow.The usual method for making casts of objects, particularly parts of thehuman body, involves the use of a substance, such as plaster of Paris,involving many disadvantages. In the first place, if we are dealing witha member of the human body, such as a foot, the plaster of Paris must bemixed precisely so that it will harden within a given time or else thepatient will be kept waiting too long to his discomfort and possibleinjury.

It is, therefore, an object of my invention to provide a new method forforming casts or molds in which the mold material is instantaneouslyavailable without mixing. It is a further object of my invention to makea mold which can be processed from dry material obviating the discomfortand messiness which is associated with the material of plaster of Paris.

I accomplish these objects by the use of a phenolic foam in my processfor making molds or impressions. In the accompanying drawings Figure lis a perspective view of a box containing a quantity of phenolic foam;

Figure 2 is a perspective view of the box shown in Figure 1, with thefoot of a person pressed into the foam for the purpose of forming themold.

Similar numerals refer to similar parts throughout the several views.The phenolic foam may be contained in a cardboard box 11 or a box ofsuitable material. I make no claim for the material of the foam. It ismanufactured from foarnable resin and may be made in varying densitiesby varying the ingredients. When it is com pressed, the crushing actionof the compression breaks down the cells of the foam and it will notspring back. It is therefore an ideal substance for making a mold of anyobject which is pressed into it. It will retain the exact configurationof the object. This type of foam may be obtained commercially fromvarious companies in the United States.

While it may be used in many ways as a molding device, I will illustrateits use in this specification in a process for making casts of feet 12.The foam 10 is set up in a box 11 of a suitable size to receive a humanfoot 12. The foot 12 is then placed over the foam at right angles to thepatients leg and in this position is pressed into the foam 10. The foot12 may then be removed from the foam 10 immediately. Since the pressureof the foot 12 on the foam 10 breaks down the cells of the foam 10 andthey do not spring back into position, a perfect mold of the foot hasbeen made. A solution of plaster of Paris is then poured into the moldand allowed to harden or the mold form may be sprayed or painted with avarnish to fix it in position.

It will be appreciated that in my process the plaster of Paris solutionmay be permitted to harden as quickly or slowly as desired. After theplaster of Paris cast is removed from the mold, it is a perfectreproduction of the bottom of the foot 12.

While I have described the preferred form of my'invention, the foam maybe used in many different ways for making molds and casts Withoutdeparting from the essential process of my invention and I thereforewish to be protected within the limits of the claim following.

Wherefore, I claim:

A process of obtaining an exact mold of any member of the body, whichcomprises preparing a block of set phenolic resinous foam; then placingthe block of set foam, of a type which becomes stiff when set and willretain the impression of a form impressed thereon on a platform; thentaking the member of the body of which it is desired to obtain a moldand impressing same into the set foam in order to make a negativeimpression; then lifting the said member of the body out of the negativeimpression so formed; then pouring a solution adapted to be hardened,into the negative impression thus formed in the set foam, and permittingthe aforesaid solution to harden into an exact positive mold.

References Cited in the file of this patent UNITED STATES PATENTS1,926,916 Reeves Sept. 12, 1933 2,282,908 Thompson May 12, 19422,547,419 Sugarman et al Apr. 3, 1951 2,565,758 Covino Aug. 28, 19512,576,911 Amos Dec. 4, 1951 2,722,719 Alstader Nov. 8, 1955

